The field of this invention relates to an apparatus for filling or circulating fluids in tubulars for running in or coming out of the wellbore, and for recovery of fluids displaced when running in tubulars in the wellbore.
When tubulars are being run or pulled from a wellbore, it is often necessary to fill the tubular, take returns from the tubular, or circulate fluid through the tubular to the lowest point in the wellbore to condition the fluid system or the wellbore or to control a xe2x80x9ckickxe2x80x9d or high pressure surge from the well. Previous devices for filling and circulating the wellbore are firmly attached to the traveling block, in the case of a conventional rig, or to the top drive, in the case of a top drive-equipped rig. In either case a very precise spacing is required of the seal assembly relative to the tubular and elevators. In the case where slip-type elevators are used, the spacing of the seal could be such that when the elevators were near the upset of the tubular, the seal could be out of the tubular. When required, the slips at the rig floor must be set on the tubular and the traveling block or top drive lowered in order to move the seal into sealing engagement with the tubular. This required that the running or pulling of the tubular stop until the slips were set at the rig floor and the seal engagement was made. This is not desirable when a well kick occurs or fluid is overflowing from the tubular. It must be noted that slip-type elevators are used infrequently due to their size, weight, and the time required to latch and unlatch them since they must be placed over the top of the tubular and lowered to the desired location in order to latch and grip the tubular, a process that is almost impossible when tubulars are racked back in the derrick and the top of the tubular is far above the derrick man""s head.
In the case where xe2x80x9cside doorxe2x80x9d or latching elevators are used, the spacing of the seal system is even more critical and the seal must be engaged in the tubular prior to latching the elevators below the upset portion of the tubular. This requires that the seal be engaged in the tubular at all times that the elevators are latched on the tubular. When tubulars are racked back in the derrick such as drill pipe or a work string, it would be very time-consuming if not impossible to insert the seal into the tubular prior to latching the elevators with the top of the tubular far above the derrick man. Also, with the seal engaged in the tubular at all times, this is a disadvantage when there is a need to access the top of the tubular while the tubulars are in the elevators or when the tubular is being filled with fluid and the air in the tubular begins to be entrained in the fluid column rather than escaping the tubular. For example, if a high-pressure line was to be attached to the tubular and the tubular moved at the same time, all previous devices had to be xe2x80x9claid downxe2x80x9d to allow a hard connection to be made to the tubular since they are in the way of the tubular connection.
It will be seen that the invention described in this application, with its extending and retracting features and the ability to easily connect to or disconnect, seal or unseal from the tubular, is very advantageous during any of the operations involved in well control, drilling, completion, workover, fishing or running and pulling the tubular, and eliminates all of the disadvantages of the prior art.
When tubular such as casing is run into a wellbore, each successive stand is attached and filled with mud as it is run into the wellbore. As the casing or tubing advances into the wellbore, a certain amount of mud is displaced. If the casing is open-ended on bottom or has a check valve, advancement of the casing or tubular into the wellbore will force mud from the wellbore uphole. If the tubular or casing is installed in a situation of fairly tight clearances, rapid advancement of the tubular into the wellbore will result in significant flow of mud through the tubular onto the rig floor area. Conversely, when attempting to pull the tubular out of the wellbore, resistance to extraction can be experienced and consequently xe2x80x9cswabbed inxe2x80x9d unless compensating fluid can be added into the wellbore to maintain sufficient hydrostatic pressure created by extraction of the tubular. Thus, there arises a need for a device which will simply allow capturing of any displaced returns during advancement of the tubular or, alternatively, allow rapid filling of the tubular for insertion into or extraction out of the wellbore.
Another situation that needs to be dealt with during these procedures is the ability to handle sudden surges of pressure from the formation to the surface. In these situations, it is desirable to be able to secure a valve in the string connected to the mud supply so that the pressure surge from the wellbore can be contained. Thus, an objective of the present invention is to allow rapid connection and disconnection to a tubular being added or removed from a string during insertion or removal operations, while at the same time allowing rapid threaded connection to the string with an integral valve which can be manually or automatically operated so as to shut-in the well and thereafter control the well by applying fluid behind the valve which has been used to control the pressure surge from the formation.
It is yet another object of the present invention to allow a system of rapid connection and disconnection to the tubular for filling or capturing of returns with minimal or no spillage in the rig floor area.
It is another object of the present invention to allow circulation of fluid at any time during rig operations for conditioning the wellbore, fluid system, or controlling a kick.
Prior systems relating to techniques for filling casing are disclosed in U.S. Pat. Nos. 5,152,554; 5,191,939; 5,249,629; 5,282,653; 5,413,171; 5,441,310; and 5,501,280, as well as U.S. Pat. No. 5,735,348.
The objectives of the present invention are accomplished through the designs illustrated and described below where the preferred embodiment and alternative embodiments are specified in greater detail.
Multiple embodiments of a system for capturing displaced fluid or adding fluid to tubulars being run into or out of the wellbore are described. Several embodiments are supported by a top drive with telescoping features to rapidly seal over a tubular to connect the tubular to a mudline. A flapper valve in one embodiment is described to keep fluid from spilling when the apparatus is removed from the tubular. In the event of a well kick, the valve can be shattered with pressure from the mudline. In another embodiment, the apparatus can be placed in sealing contact with the tubular and can incorporate a valve which can be manually closed in the event of a well kick. In yet another alternative, the incorporated valve can be automatically actuated to open as the apparatus sits on the tubular and closed as the apparatus lifts from the tubular. In yet another embodiment, sealing contact with the tubular can be obtained by simply advancing the apparatus into the tubular.